The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Evaporative emissions control systems are used to capture and contain fuel vapors generated in fuel tanks of vehicles and stationary storage systems. Known systems include vapor storage devices connected via vapor lines to a fuel tank. Known systems include vapor storage devices having a vent line connectable to atmospheric air and a purge line connectable to a vacuum source, e.g., an intake manifold of an internal combustion engine.
Fuel vapor can be generated in the fuel storage tank and stored in the vapor storage device ongoingly, including fuel vapor generated due to variations in ambient temperature over time, referred to as diurnal fuel vapor. Stored fuel vapor can be purged from the vapor storage device by air flow through the vapor storage device, e.g., when low pressure is introduced to the purge line and air is drawn through the vapor storage device through the vent line.
An extended range hybrid vehicle primarily uses one or more electric machines for primary propulsion and an internal combustion engine as a back-up propulsion or charging system to extend driving range beyond that achievable with only an electric machine and an on-board electrical energy storage device. An extended range hybrid vehicle includes a plug-in electric charging system that connects to a stationary electric outlet connected to an electric grid to charge vehicle batteries during periods when the vehicle is not operating. The internal combustion engine connects to a fuel tank. The fuel tank may generate diurnal fuel vapors that can be captured and stored in one or more vapor storage devices of an evaporative emissions control system. Purging of the fuel vapor stored in the vapor storage device may not occur for an extended time period. If the vapor storage device is not purged, the vapor storage device may saturate and release any subsequently produced fuel vapor into the atmosphere.
An extended range hybrid vehicle may operate for extended periods of time, e.g., days and weeks, without operating the internal combustion engine when the vehicle is used for short distance commuting, resulting in no purging of vapor stored in onboard vapor storage device(s).